A rolling bearing device which incorporates an oil supply unit therein is conventional (see JP 2004-108388A). In this rolling bearing device, an oil supply unit is mounted on an inner diameter surface of one of two mutually opposed track rings of the rolling bearing, or a fixed-side track ring in this case. The oil supply unit includes a lubrication oil tank which stores lubrication oil; a pump which pumps out the lubrication oil stored in the lubrication oil tank into the bearing; and an electric power generator which drives the pump. The device also includes means which controls the pump in accordance with bearing conditions thereby controlling an amount of discharged oil.
JP 2005-180629A discloses a rolling bearing device, which is loaded with grease therein. A lubrication oil of the same kind as the base oil of the grease is stored in a spacer adjacent to the rolling bearing. The lubrication oil inside the spacer is supplied to inside of the rolling bearing by means of capillary action.
However, the arrangement such as disclosed in JP 2005-180629A, that lubrication oil inside the spacer is supplied to inside of the rolling bearing by capillary action, often results in excessive supply of the lubrication oil.
Also, the lubrication oil stored in the spacer is consumed quickly, posing a problem that stable, long-term supply of lubrication oil is impossible.